This study proposes to examine the effects of a 12 week low-moderate intensity aerobic exercise program on selected disease-related outcomes in patients with HIV but without CDC-defined AIDS.Outcome measures include assessments of physical symptoms; immune markers; depression; mood states and aerobic power. This is an important study. The aims are clearly stated, with variables identified, defined, and operationalized in exceptional detail. The review of the literature is comprehensive, current and analytic.Earlier work by the investigators serves as a firm foundation for the proposed study. The independent variable and all dependent variables are identified, defined, and operationalized. Inclusion/exclusion criteria are provided, most of which are appropriate. This study has numerous strengths all of which are not mentioned above but are fairly accurately discussed in the reviewers' comments. Some of the key weaknesses concern the sample size; feasibility and generalizability; the ability of the measures to detect clinically meaningful change over time; and the antiretroviral stratification. While the outcome measures are appropriate and could yield significant information, there are also some concerns related to the enrollment of control subjects in the experimental treatment before long-term outcomes are assessed, and the need to adequately monitor for the potential adverse effects of the treatment. There are also lesser concerns about the usefulness of measuring three of the extraneous variables. The team as a whole is highly competent to perform this research. Appropriate consultants have been chosen to assist with statistical analyses and data interpretation. Laboratory resources for this project are very appropriate including exercise testing and training facilities, clinical evaluation sites, and the laboratory for immunophenotyping.